Telephonic apparatus.



c. FORGUES.

TELEPHONIG APPARATUS.

APPLICATION FILED AUG-3,1914- I l gh Patented June 26, 191?.

3 SHEETS-SHEET I.

C. FORGUES.

TELEFHONIC APPARATUS. APPLICATION FILED Aue.a. 1914. L m aa Patented June 26, 191?.

3 SHEETS-SHEET 2.

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TELEPHONIC APPARATUS.

APPLICATION FILED M163, 1914.

L m wh Eatented June 26, 19M.

3 SHEETS-SHEET 3.

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CHARLES FORGUES, OF PIS, FRANCE, ASSIGNOR T SOCIETE DE LAVANDEYEA &

- OBNER, 0F PARIS, FRANCE. 7

I TELEPHONIG APPARATUS.

. Specification of Letters Patent.

Patented June 26, 11917.

Application filed August 3, 1914. Serial No. 854,846.

' To all whom it may concern:

group. Its hygienic quality is due Be it known that 1, CHARLES Fonouns, a citizen of .the French Republic, residing at Paris, France, 8 Rue de Moscou, have invented new and useful Improved Telephonic Apparatus, of which the following is a speclfication.

This invention relates to an intensive and hygienic telephonic apparatus of the net type. Its intensive quality is due to the use of a sensitive and powerful micro-telephone to the construction and general arrangement of the apparatus which in the state of rest, is

wholly 1nclosed in an air-tight and nonheat-conduct ng box, the interior of which hasbeen rendered antiseptic.

The improved apparatus comprises three main parts 1. A micro-telephone constituted by the general arrangement of a microphone and a receiver.

2. An automatic switch; and

3. A box which, when the apparatus is in its state of rest, is closed by the microphone that forms a lid or cover.

One form of this invention is illustrated by way of example in the accompanying drawings Figure 1 is a vertical section of the general arrangement ,of the improved apparatus, taken on the line 1-1 of Fig. 2.

Fig. 2 is an underside view corresponding to Fig. 1, without the bottom plate.

Fig. 3 is an inside view of the microphone without the diaphragm.

Fig. at is a section on the line 4.-4: of Fig. I viewed from underneath, some parts being shown in external elevation.

Fig. 5 is an elevation ofthe micro-telephone, vicwed from the side of the receiver.

Fig. 6 is a plan corresponding to Fig. 1, without the micro-telephone.-

The micro telephone (or monophone) forms a removable whole comprising a twofaced microphone A and a magnetic receiver B with compensated inertia (Figs. 1, 3 and 5). This whole is differentiated from the apparatus hitherto known, by the complete absence of an acoustic horn or funnel for guiding the are usually introduced by acoustic horns or funnels.

The microphone A (Figs. 1 and 3) is of the two-faced type. The face a of the mi-. crophone is affected directly by the sound waves, because it remains in free and permanent communication with the outer atmosphere through the medium of passages a. The face a of the microphone is affected by the waves which arereflected by the reflector a and which reach the reflector through apertures a provided between the body of the micro-telephone and the periphery of the reflector.

The part a which covers the face a of the microphone is recessed in such a manner as to form a basin-shaped member in which the parts of the receiver B are situated.

The main difficulty resides in the establishment of the functional relations between the magnet and the coils, owing to the fact that said relations constitute an extremely delicate problem, namely that of efiecting syntonous action between the microphone and the receiver.

The variation of the magnetism of a magnet is produced by means ofvariations of intensity caused by the current flowing in the polarized coils, and these lattervariations are caused by variations of conductivity produced by the infinitely small differences in pressure of the sound waves acting upon the carbon contacts when the said waves strike the diaphragm.

The result of this is that for the purpose of assuring a maximum amplitude of the variations of magnetism of the magnet, recourse must be had to very powerful microphones, that is to say microphones which are provided with very sensitive multiple contacts, and recourse must also be had to anelectrical device which will transmit integrally the microphonic phenomena and concentrate them powerfully in the receiver.

Finally, the means. which subjects the magnet to the control or influence of the microphonic variations, is the intermittent current, the effort of which is concentrated by the use of coils, which is equivalent to Saying that the concordance between the receiver and themicrophone is assured by the said coils.

Unfortunately however, since the magnet has its own coercive force, it can translate these facts,

' ing them. The aberration the microphonic functions only by deformof inertia is the more powerful the greater the coercive force of the magnet. Now since this latter value depends directly on the power of the magnet, it is recognized that the sonorous properties, namely the intensity and clearness of a magnetic telephone, depend less on the actual power of the magnet employed than on the amplitude of the variations to which this magnetic value is subjected.

A'rational construction should, basing on assure to the current flowin in the coils which, in the present case, 1s a transforming current, the capacity necessary. for its functions.

' present case by the coils.

On the other hand the internal field of a solenoidto which every coil may be assimilated-does not depend in any way on the diameter of the turns, but solely on the product 11. I, that is to say, on the number of turns per centimeter multiplied by the intensity expressed in amperes of the current. 1

Since the value of the factor I of this product is restricted as above stated by reasons of economy and the constructional practicability of the microphone, an increase in the value of this product can be effected only by increasing the factor n, that is to say by increasin the number of turns.

In order to satlsfy these data special coils B have been constructed with which the present improved telephone is provided. In these coils the internal field exerting its powerful effect upon the ma et, has a tendency to annul the inertia o the said magnet; whence its name :receiver with compensated inertia.

6 (Figs. 1 and 1) is a soft iron core having a reinforced base I). The free end 6 of this core is set at right angles to the base. To this first core, one-or more other identical cores 6 are added according to the dimensions which it is desired to give tothe coils. The cores 6, b are covered with an insulated conductor of very small section so as to obtain a large number of turns to ether with a high electrical resistance. T e direction of the winding is the same for all the cores. The windings of the various cores are connected up 1n series.

The cores furnished with the necessary number of turns and connected up are fastened together by means of the screw 6 in such a manner as to constitute only one piece which is then to be considered as a polarized armature of the magnet, and? which is covered with a number of layers of turns 6 arranged in the same direction as those on the cores 6, b. This second coil 6* which surrounds the first coils is likewise mounted in series with the coils of the cores. By this means a total coil of elliptical cross section is obtained. The advantage of this arrangement consists in that a very large number of turns is collected in a very small space and consequently a very powerful magnetic field is created.

The direction of the winding on the second polarized coil B is contrary to that of the first coil. The coils thus constructed are fixed by means of the screw 6 in suitable recesses b formed in the actual magnet D.'

' In addition to the two polarized coils B the receiver with compensated inertia comprises vtwo other coils 6 with a polarized core, since the magnet D serves as a core for these two last coils. For this purpose the magnet D is made of two identical parts.

For a certain portion (2 of their development the. section of cular.

The sections of a ring thus produced serve as cores for the two coils e, the directions of winding of which are reversed. The coils e are mounted in series relatively to each other and constitute a shunt relatively to the polarized coils B. By this means the inertia which is opposed by the whole to the variations produced by the microphonic op erations, tends to become 11.27. The apparatus which is perfectly syntonous to the sound waves has a remarkable power and clearness.

The switch consists of a rod 7 having a polygonal head f adapted to move inside a guide tube f in which the polygonal head f can slide freely. Between the rod 7 and the guide tube 7 there is arranged a coil spring i bearing at one end against the polygonal head '7, and at its other end against a partition 9 of the box G.

The rod 7 carries at its lower end a plate f upon which are mounted plunger-contact pieces. Each of these contact pieces consists of a nipple f movable in a recess and butting against a spring f When the microphone is lifted for the purpose of using the apparatus, the switch rises. The contact pieces F then bear upon the magnet D is cirthe conducting bars h carried by the parti tion 9, and they make the necessary connections for the operation of the apparatus. The connectlons are agaln interrupted autophone .ing bars it and.

matically when after using the apparatus, the microphone is replaced upon its rest.

The box G inclosing the parts has been assumed to be of truncated conical shape, but it may have any other shape. In the position of rest of the apparatus the microforms a cover or lid, the edges of thereflector a fitting directly upon the upper edge of the box G. 7

he partition 9 which carries the connectthe switch, carries likewise the induction coil '11 (Figs. 1, 2 and 6) whose contacts can be readily operated through the p an antiseptic cartridge 1n sald bottom of the aperture 9 The partition 9 is also provided with holes 9 to allow of a free circulation of air inside the box G. The box G is closed at its lower end by a screwed bottom 9 (Fig. 1). The bottom 9 carries a cartridge 7' of antiseptic substance, the vapors of which pass freely inside the box for the purpose of disinfecting the parts of the apparatus. The cartridge j can be readily introduced from the outside without it being necessary to open the box G.

Swmnai'y.

The invention comprises In a telephonic apparatus of the character described, in combination, a casing, a bottom screwed into said casing, a micro-telephone or monophone comprising a hornle$, two-faced micro-phone and a receiver within said casing, said micro-telephone constituting in the position of rest of the aparatus the cover or lid for said casing, and

casing, substantially as described.

In testimony whereof I aflix my signature in presence of two wltnesses.

C E LES FORGUES.

Witnesses:

ELY E. P MIGUEL Fnnono. 

